Currently, ShippingEasy does not send you or your customer a Shipment Confirmation e-mail for drop shipped ("Mark as Shipped") orders. Only orders with labels generated in ShippingEasy will receive the Shipment Confirmation email. However, using "Marked as Shipped" does update your SHIPMENT HISTORY page and your website with the tracking number.
How to: Mark an order as shipped
How to: Add a tracking number to drop shipped orders
How to: Return an order that was drop shipped or not in my Shipment History
Know How: Capitalize on packing slips + notification emails
How to: Create a custom Email Template and save it to your store